Fayat BOMAG BC 462 RB, Service Manual

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1.3
General repair instructions
BOMAG 14 008 917 13
1.3 General repair instructions
General
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Before removing or disassembling parts, assem-
blies, components or hoses mark these parts for
easier assembly.
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Before assembling and installing parts, assemblies
or components oil or grease all movable parts or
surfaces as required and in compliance with the
compatibility of materials.
Electrics
General
Due to the fast technical development electric and
electronic vehicle systems become more intelligent
and more comprehensive day by day, and can hardly
be dispensed with in hydraulic and mechanical vehicle
systems.
Diagnostics according to plan
Well structured trouble shooting procedures can save
time and money.
Random tests have revealed that purely electronic
components or control units only very rarely are the
actual cause of failures:
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In approx. 10 % of the examined cases the prob-
lems were caused by control units.
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In approx. 15 % sensors and actuators were the
cause of the problems.
By far the highest proportion of all faults could be
traced back to wiring and connections (plugs, etc.).
General:
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Before changing any expensive components, such
as control units, you should run a systematic trouble
shooting session to eliminate any other possible
fault sources. Knowledge in basic electrics is re-
quired for this purpose. If a fault was diagnosed
without having pulled the plug of the control unit or
inspected the wiring, this should be done before
changing any parts.
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Check for good cable and ground contacts, there-
fore keep all mechanical transition points between
electric conductors (terminals, plugs) free of oxide
and dirt, as far as this is possible.
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Always use the machine related wiring diagram for
testing. If one or more faults were detected, these
should be corrected immediately.
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Do not disconnect or connect battery or generator
while the engine is running.
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Do not operate the main battery switch under load.
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Do not use jump leads after the battery has been re-
moved.
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Sensors and electric actuators on control units must
never be connected individually or between exter-
nal power sources for the purpose of testing, but
only in connection with the control unit in question.
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It is not permitted to pull plugs off while the voltage
supply is switched on (terminal 15 "ON")! Switch the
voltage supply "OFF" first and pull out the plug.
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Even with an existing polarity reversal protection in-
correct polarity must be strictly avoided. Incorrect
polarity can cause damage to control units!